Key seat wiper



Sept. 13, 1955 G. E. CANNON 2,717,764

KEY SEAT WIPER Filed D90. 12, 1950 INVENTOR. George E. Co nnon,

AGENT.

KEY SEAT WIPER George E. Cannon, Houston, Tex., assignor, by mesne assignments, to Esso Research and Engineering Company, Elizabeth, N. J., a corporation of Delaware Application December 12, 1950, Serial No. 200,477

3 Claims. (Cl. 255-27) The present invention is directed to an apparatus suitable for use in reaming or enlarging key seats in boreholes. More particularly, the invention is directed to a combination apparatus with a drill stem including a device for reaming key seats in boreholes.

The invention may be briefly described as involving a combination with a drill string having a drill pipe and a drill collar of a device for reaming key seats in boreholes which comprises a sleeve or mandrel rotatably mounted on the drill pipe which defines with at least one end thereof a driving lug or a plurality of driving lugs. A sub or tool joint attached to said drill stem defines a driving jaw which is engageable with the lugs and is adapted to cause rotation of the sleeve on rotation of the drill pipe.

The invention will be further illustrated by the drawing in which the single figure is an elevational view of a preferred embodiment thereof.

Referring now to the drawing, numeral 11 designates a. mandrel which may suitably be a drill pipe mounted on which is a sleeve 12 which is adapted to rotate freely on the mandrel 11. The sleeve 12 defines with first and second ends thereof driving lugs 13 which are adapted to engage with a driving jaw 14 arranged on a bumper sub 15 or on a tool joint 16 as the case may be. The sleeve 12 has a length substantially less than the length of the mandrel 11 between sub 15 and the tool joint 16. The exterior surface of the sleeve 12 defines therewith a plurality of lands 17 longitudinally arranged therein and which may describe a helical pattern on the exterior surface of the sleeve. The sub 15 and the tool joint 16 are arranged suitably in a drill string.

In the drilling of oil and other types of wells there is a tendency for the drill bit to deviate from the vertical. At times it may be intentional to deviate the borehole from the vertical especially during the drilling of directional holes. At times when the borehole deviates either intentionally or unintentionally a slot or key seat is formed in the borehole wall on the low side of the hole on a reversal of direction and on the high side of the hole when the deviation is in one direction. The slot or key seat is a result of the tendency of the pipe to ride these points when being pulled. The inside diameter of the slot is frequently the same as the outside diameter of the tool joints. A tool string generally consists of drill collars near the top of the bit which are larger in diameter than the tool joints or pipe yet smaller than the bit. When this larger diameter of pipe is pulled into the slot the upward travel is interrupted and often the drill collars are stuck at the entrance of the slot. This is especially true if the drill pipe is being pulled at high speeds and no warning of key seats is given.

The device of the present invention allows the elimination or the enlargement of key seats by providing in a drill string in combination therewith a mandrel having a rotatable sleeve mounted thereon of a length less than the length of the mandrel and which may be rotated on rotation of the drill stn'ng. On coming out of the hole States. Patent 0 ice with the device of the present invention, when the drill pipe becomes stuck, the sleeve would be positioned such that it would be adjacent the tool joint 16 and the driving lug 13 would be engaged with the jaw on the tool joint 16. On rotation of the drill string the lands 17 would enlarge or ream out the key seat and allow freeing of the stuck drill pipe. Similarly, when going into the hole, when the drill pipe becomes stuck, the sleeve 12 would be adjacent the bumper sub 15 and the lugs 13 would engage with driving jaw 14 on sub 15 allowing the sleeve to rotate and the lands 17 to ream out the key seat. It is thus possible to engage the driving lugs 16 with the jaw 14 on the tool joint or on the sub as the case may be. This may also be accomplished by picking up or setting down the drill pipe to engage the lugs 16 with either of the jaws 14 when the pipe becomes stuck in a key seat.

A feature of the present invention is the provision of a driving mechanism of sturdy construction and yet which can be rotated freely on the mandrel. Another feature of the invention is a sleeve having the same diameter as the diameter of the tool joint or the sub which allows removal of key seats by rotation of the sleeve.

The nature and objects of the present invention having been completely described and illustrated, what I wish to claim as new and useful and to secure by Letters Pateat is:

l. A device for use in combination with a drill string for reaming key seats in boreholes which comprises a mandrel, a sub attached to said mandrel on a first end having a downwardly projecting extension defining a first driving jaw, a sleeve rotatably mounted on said mandrel for free rotation with the drill string having a length less than the length of the mandrel, said sleeve being provided with first and second driving lugs on first and seconds ends thereof, the outer surface of said sleeve having reaming lands, a tool joint attached to said mandrel on a second end having an upwardly projecting extension defining a second driving jaw, the diameter of said sleeve being no greater than the diameter of said tool joint, said lugs on said first end of the sleeve and on said second end of the sleeve being independently engageable with said first and second driving jaws, respectively, and adapted to cause rotation of the sleeve on rotation of the drill pipe, the first and second ends of said sleeve each providing a plane, substantially circumferential surface, said sub and said tool joint each also providing a plane, substantially circumferential surface opposing the surfaces on the first and second ends of the sleeve, the first and second ends of said sleeve always being spaced from said sub and from said tool joint and being interconnected therewith frictionally only by said independent engagement of the first and second lugs with the first and second driving jaws, said first and second lugs and said first and second driving jaws extending only partially and a minor distance around said plane, substantially circumferential surfaces such that said driving jaws and said driving lugs rotate on the opposing surface before engaging with each other.

2. A device for use in combination with a drill string for reaming key seats in boreholes which comprises a mandrel, a sub attached to said mandrel on a first end having a downwardly projecting extension defining a first driving jaw, a sleeve rotatably mounted on said mandrel for free rotation with the dn'll'string having a length less than the length of the mandrel, said sleeve being provided with first and second driving lugs on first and second ends thereof and with an outer surface a plurality of longitudinally arranged lands, a tool joint attached to said mandrel on a second end having an upwardly projecting extension defining a second driving jaw, the diameter of said sleeve being no greater than the diameter of said tool joint, said lugs on said first and second ends of said sleeve being engageable independently with said first and second driving jaws, respectively, and adapted to cause rotation of the sleeve on rotation of the drill pipe, the first and second ends of said sleeve each providing a plane, substantially circumferential surface, said sub and said tool joint each also providing a plane, substantially circumferential surface opposing the surfaces on the first and second ends of the sleeve, the first and second ends of said sleeve always being spaced from said sub and from said tool joint and being interconnected therewith frictionally only by said independent engagement of the first and second lugs with the first and second driving jaws, said first and second lugs and said first and second driving jaws extending only partially and a minor distance around said plane, substantially circumferential surfaces References Cited in the file of this patent UNITED STATES PATENTS 2,072,320 Thomas Mar. 2, 1937 2,212,067 Hoffoss Aug. 20, 1940 2,572,307 Brown et a1. Oct. 23, 1951 OTHER REFERENCES Burris Key Seat Wiper Drill Collar Assembly, by J. J. Burris; October 1946. 

